1. Field of the Invention
The present invention relates to a vertical power unit and an outboard engine system comprising: an engine which has a vertically arranged crankshaft; a vertically arranged output shaft provided below the crankshaft; and a torque converter disposed between the crankshaft and the output shaft, the torque converter including: a pump impeller connected to the crankshaft; a turbine runner connected to the output shaft so as to opposed to the pump impeller; a stator arranged between the pump impeller and the turbine runner; and a circulation circuit of a power transmission oil, the circuit being defined between the pump impeller, turbine runner and stator; and a vertical hole which is provided in the output shaft and which communicates at an upper end with the circulation circuit so as to introduce the oil discharged by the oil pump into the circulation circuit.
2. Description of the Related Art
U.S. Pat. No. 3,407,600 discloses a vertical power unit and an outboard engine system which includes an engine having a vertically arranged crankshaft, a vertically arranged output shaft below the crankshaft, and a torque converter disposed between the crankshaft and the output shaft.
In the vertical power unit and the outboard engine system disclosed in U.S. Pat. No. 3,407,600, the torque converter includes a built-in oil reservoir for storing an working oil, and a sealed-type circulation circuit. Therefore, the torque converter inevitably becomes large to increase the weight, while enlarging a surrounding part. Further, the working oil in the sealed-type torque converter obtains a poor cooling, thereby accelerating deterioration of the oil.